N-phosphono methylene amino alkane phosphonic acid compounds, process of producing same, and method and compositions of using same

ABSTRACT

Valuable and highly water soluble N-phosphono methylene mono- and di-amino alkane mono- and polyphosphonic acids which have not only an &gt;N--CH 2  --PO 3  H 2  group but also a  C--PO 3  H 2  group in their molecule are produced by reacting amino alkane mono- or diphosphonic acids with formaldehyde and phosphorous acid or alkane nitriles with phosphorous acid, formaldehyde, and concentrated hydrochloric acid. The resulting phosphonic acid compounds are valuable sequestering agents forming complex compounds with bi- and polyvalent metal ions. They are useful for water softening even in substoichiometric amounts, in textile treatment baths, in the paper manufacture, in tanning baths, for the manufacture of liquid fertilizers, and for other purposes.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to novel and valuable phosphonic acidcompounds and more particularly to N-phosphono methylene mono-aminoalkane mono- and polyphosphonic acids and to N-phosphono methylenediamino alkane polyphosphonic acids, to a simple and effective processof making such compounds, to methods of using same, and to compositionscontaining same.

(2) Description of the Prior Art

It is known to react amino carboxylic acids with aldehydes or ketonesand compounds of trivalent phosphorus, such as phosphorus trichloride orphosphorous acid. Thus, for instance, according to British Pat. No.1,142,294 or according to German Published Application No. 12 14 229,there is obtained the corresponding phosphono carboxylic acid byreacting glycine with formaldehyde and phosphorus trichloride in thepresence of water or phosphorous acid.

SUMMARY OF THE INVENTION

It is one object of the present invention to provide novel andadvantageous N-phosphono methylene mono-amino alkane mono- andpolyphosphonic acids or N-phosphono methylene di-amino alkanepolyphosphonic acids which have proved to be highly valuable compounds.

Another object of the present invention is to provide a simple andeffective process of making such novel phosphonic acid compounds.

Still another object of the present invention is to provide compositionscontaining such novel amino alkane phosphonic acid compounds, suchcompositions being useful for various technical applications.

Other objects of the present invention and advantageous features thereofwill become apparent as the description proceeds.

In principle, the novel N-phosphono methylene amino alkane phosphonicacid compounds according to the present invention correspond to thefollowing formula ##STR1## In said formula N IS A NUMERAL FROM 0 TO 4;

R₁ represents hydrogen,

Alkyl with 1 to 11 carbon atoms in its hydrocarbon chain,

Hydroxyl,

An alkylene phosphonic acid group of the formula --(CH₂)_(n).PO₃ H₂,

the hydroxy ethylene group of the formula --C₂ H₄ OH,

an alkylene carboxylic acid group of the formula --(CH₂)_(n).COOH,

an amino alkylene group of the formula ##STR2## and an 1-aminoalkane-1,1-diphosphonic acid group of the formula ##STR3## R₂ indicateshydrogen or the phosphonic acid group; R₃ indicates hydrogen or themethylene phosphonic acid group; and

R₄ indicates the methylene phosphonic acid group.

The novel phosphonic acid compounds according to the present inventiondiffer from the heretofore known compounds more particularly by thefeature that they contain, in addition to the group >N--CH₂ --PO₃ H₂also the group C--PO₃ H₂.

Compounds of this type are, for instance, the N-phosphonomethylene-1-amino alkane phosphonic acids which may contain up to 11carbon atoms in their alkane chain.

Other compounds which are comprised by the above-given general formulaare the N-phosphono methylene-1-aminoalkane-1,1-diphosphonic acids whichmay also have up to 11 carbon atoms in their alkane chain.

A further group of compounds according to the present invention are theN-phosphono methylene-1-amino-3-phosphono alkane phosphonic acids.

Futhermore, N-phosphono methylene-1-amino-3-hydroxy alkane diphosphonicacids as well as the N-phosphono methylene-1-amino-ω-carboxy-1,1-alkanediphosphonic acids and the N,N-bis-phosphono methylene diamino alkanetetraphosphonic acids are also to be mentioned.

Amino alkane phosphonic acids are used as starting materials in order toproduce the compounds according to the present invention. Said startingmaterials are subjected to a phosphono alkylation with carbonylcompounds and phosphorous acid or phosphorous trichloride in thepresence of water. Preferably aliphatic aldehydes, especiallyformaldehyde, and ketones are used as carbonyl compounds.

The novel phosphonic acids of the present invention thus can be producedaccording to the following two processes.

Process A

Amino alkane mono- or, respectively, polyphosphonic acids of the formula##STR4## in which n is a numeral from 0 to 4;

R₁ is hydrogen,

alkyl with 1 to 11 carbon atoms in its hydrocarbon chain,

hydroxyl,

a hydroxy ethylene group of the formula --C₂ H₄ OH,

an alkylene phosphonic acid group of the formula --(CH₂)_(n).PO₃ H₂,

an alkylene carboxylic acid group of the formula --(CH₂)_(n) --COOH,

an amino alkylene group of the formula ##STR5## or an aminoalkane-1,1-diphosphonic acid group of the formula ##STR6## R₂ ishydrogen or the phosphonic acid group; and R₃ and R₄ are hydrogen,

are used as starting materials.

Said starting phosphonic acids are reacted with formaldehyde andphosphorous acid in a proportion of at least 1:1:1.5 to 1:2:2.5. Thetemperature at which the reaction is carried out is within the range ofbetween 50° C. and about 120° C.

2-Amino ethane-1-phosphonic acid, for instance, yields, on reaction withthe corresponding amounts of formaldehyde solution and phosphorous acid,the N,N-bis-phosphono methylene-1-amino ethane monophosphonic acid.

3-Amino propane-1-phosphonic acid yields N-phosphono methylene-3-aminopropane-1-phosphonic acid on reaction with formaldehyde and phosphorousacid.

Preferably the reaction is carried out with a small excess offormaldehyde, because using smaller amounts of aldehyde and phosphorousacid than corresponding to the above stated proportions yields mixturesof di- and triphosphonic acids which can be separated only withdifficulty.

Of considerable technical importance is the reaction of geminate aminoalkane di-phosphonic acids. They yield predominantly triphosphonic acidsand, in addition thereto, small amounts of polyphosphonic acids.

Reaction of amino methane diphosphonic acid with slightly more than onemole of phosphorous acid and formaldehyde yields mainly N-phosphonomethylene amino methane diphosphonic acid. The reaction proceeds in asimilar manner with other 1-amino alkane-1,1-diphosphonic acids such as,for instance, with 1-amino ethane-1,1-diphosphonic acid or with 1-aminopropane-1,1-diphosphonic acid.

Hydroxy amino alkane diphosphonic acids yield hydroxy amino alkanetriphosphonic acids. 1,2-Diamino ethane-1,1-diphosphonic acid isconverted according to the present invention into a mixture of variouspolyphosphonic acids.

In place of phosphorous acid, there can also be used phosphorustrichloride with the amount of water required to convert it tophosphorous acid.

Process B

Phosphono alkylation for the production of amino alkane diphosphonicacids according to the present invention can be effected especiallyadvantageously by reacting alkane nitriles and phosphorous acid in themolar proportion of 1:2.5 to 1:3 at a temperature between about 140° C.and about 200° C. until a crystalline slurry, which can still bestirred, has been formed. Formaldehyde solution and preferablyconcentrated hydrochloric acid are added in the required amounts to theresulting mixture cooled to about 120° C. and the mixture issubsequently boiled under reflux. Nitriles which contain 1 to 12 carbonatoms are useful reactants for this process. Aliphatic straight chain orbranched alkane nitriles have proved to be useful. Especially preferrednitriles are acetonitrile, propionitrile, butyronitrile, lauronitrile,as well as di-alkoxy phosphono propionitrile.

The new phosphonic acids are distinguished over the prior art phosphonicacids by being readily produced in a good yield and by being highlysoluble in water. High water solubility is an important requirement formost uses of the compounds. They are excellent sequestering agents whichform complex compounds with bivalent and polyvalent metal ions and thuscan be employed with advantage in all those instances where asatisfactory sequestering power is required. Of special importance istheir resistance to hydrolysis even at a high temperature. As a resultthereof they can be employed in all those cases in which temperaturesabove 100° C. are required. Thus they can be added to all media in whichcompounds causing hardness of the water have a disturbing and obnoxiouseffect or in which the influence of polyvalent metal ions is to beeliminated. More particularly, they have proved to be of considerablevalue in the processing of hard water, as additives to baths used forthe treatment of textiles, in the manufacture of paper, and in tanningbaths.

The new phosphonic acid have also proved to be of value in stabilizingthe water hardness when added in substoichiometric amounts, i.e. forcarrying out the so-called "threshold process".

A further possibility of using the new phosphonic acids consists intheir employment for the production of liquid fertilizers. Moreparticularly, the extremely high solubility of the free acids in aqueousmedia which is lacking in most of the presently known amino phosphonicacids may be especially pointed out. In general, at least 100 g. of thecompounds described in the examples and claimed hereinafter, are solublein 100 ml. of water.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following examples serve to illustrate the present inventionwithout, however, limiting the same thereto.

EXAMPLE 1

95 g. of amino methane diphosphonic acid, 50 g. of phosphorous acid, and60 g. of a 37% formaldehyde solution are heated under reflux with 25 cc.of concentrated hydrochloric acid for two hours. As soon as a clearsolution is obtained, the water is removed completely by evaporation andthe residue is poured into 300 cc. of methanol. In this manner,non-reacted phosphorous acid is removed.

The resulting resinous residue contains mainly the N-phosphono methyleneamino methane diphosphonic acid.

EXAMPLE 2

103 g. of 1-amino ethane-1,1-diphosphonic acid are suspended in 100 g.of a 30% formaldehyde solution. 85 cc. of phosphorus trichloride areadded thereto drop by drop while stirring. After the addition iscompleted, the mixture is heated to boiling until a homogeneous mixtureis formed. The water is removed by evaporation in a vacuum. Theresulting phosphonic acid mixture is precipitated by the addition ofacetone. N-phosphono methylene-1-amino ethane-1,1-diphosphonic acid isobtained in this manner.

EXAMPLE 3

62.5 g. of 2-amino ethane-1-phosphonic acid, 85 g. of phosphorous acid,and 30 g. of trioxane are suspended in 100 cc. of water. 20 cc. ofconcentrated hydrochloric acid are added thereto. The reaction mixtureis boiled under reflux for 3 hours. The water is then removed byevaporation. The resulting mixture is repeatedly washed with acetone orbutanone in order to remove excess formaldehyde and phosphorous acid. Aproduct which consists mainly of N,N-bis-phosphono methylene-2-aminoethane-1-phosphonic acid is obtained as residue.

EXAMPLE 4

3,140 g. of phosphorous acid are dissolved in 628 g. of acetonitrile at80° C. and 1 g. of aluminum chloride is added thereto. Said reactionmixture is added drop by drop, while stirring vigorously, through adropping funnel which can be heated, into a reaction vessel which isprovided with reflux cooler and is heated to 190° C. Crystallizationsets in after about half an hour. The speed at which the reactionmixture is added drop by drop is regulated so that the temperature ofthe mixture in the reaction vessel is maintained between 170° C. and180° C. Addition of the reactants is complete after three hours. Ahomogeneous crystalline slurry which can still be stirred, is obtained.The reaction mixture is then cooled to 120° C. 3.26 liters ofconcentrated hydrochloric acid and 2.8 liters of a 36% formaldehydesolution are added thereto and the mixture is boiled under reflux forthree hours.

An amber colored solution which still contains some solid matter isobtained. After addition of 400 g. of phosphorous acid and boiling themixture under reflux for one hour, a clear amber colored solution isproduced. By thin-layer chromatographic investigation it could be shownthat the 1-amino ethane-1,1-diphosphonic acid was completely convertedinto two novel phosphonic acids and that only a small amount ofphosphorous acid and only traces of phosphoric acid are present in thesolution. One of the resulting phosphonic acids which is obtainedpredominantly has been isolated and identified by its ³¹ P-resonancespectrum as well as by its infrared spectrum and also by analysis asN-phosphono methylene-1-amino ethane-1,1-diphosphonic acid.

Analysis: Calculated: C,12.04%; N,4.68%; P,31.10%; Found: C,12.3%;N,4.9%; P,31.3%.

When using the following amino alkane phosphonic acids or alkanenitriles as the one reaction component and otherwise proceeding asdescribed in the aforesaid examples, the following compounds areobtained:

    __________________________________________________________________________                                 Prepared                                                                      according                                        Ex- Alkane     Resulting amino alkane                                                                      to                                               ample                                                                             reactant   phosphonic acid                                                                             Example                                          __________________________________________________________________________    5   1-Amino propane-1,1-                                                                     N-phosphono methylene-1-                                                                    1                                                    diphosphonic acid                                                                        amino propane-1,1-di-                                                         phosphonic acid                                                6   1-Amino hexane-1,1-                                                                      N-phosphono methylene-                                                                      1                                                    diphosphonic acid                                                                        1-amino-hexane-1,1-di-                                                        phosphonic acid                                                7   1-Amino dodecane-1,1-                                                                    N-phosphono methylene-1-                                                                    1                                                    diphosphonic acid                                                                        amino dodecane-1,1-di-                                                        phosphonic acid                                                8   3-Amino propane-1-                                                                       N,N-bis-phosphono methyl-                                                                   3                                                    phosphonic acid                                                                          ene-3-amino propane-1,1-di-                                                   monophosphonic acid                                            9   4-Amino pentane-1-                                                                       N,N-bis-phosphono methyl-                                                                   3                                                    phosphonic acid                                                                          ene-4-amino pentane-1-                                                        monophosphonic acid                                            10  1,2-Diamino ethane-                                                                      Mixture of N-phosphono-                                                                     2                                                    1,1-diphosphonic                                                                         methylene substituted                                              acid       1,2-diamino ethane-1,1-                                                       diphosphonic acids                                             11  1-Amino-3-carboxy                                                                        N-phosphono methylene-1-                                                                    3                                                    propane-1-phosphonic                                                                     amino-3-carboxy propane-                                           acid       1-phosphonic acid                                              12  Propionitrile                                                                            N-phosphono methylene-1-                                                                    4                                                               amino propane-1,1-di-                                                         phosphonic acid                                                13  Lauronitrile                                                                             N-phosphono methylene-1-                                                                    4                                                               amino dodecane-1,1-di-                                                        phosphonic acid                                                14  Diethoxy phosphono                                                                       N-phosphono methylene-                                                                      4                                                    propionitrile                                                                            3-phosphono-1-amino                                                           propane-1,1-diphosphonic                                                      acid                                                           15  1-Amino pentane-1,1-                                                                     N-phosphono methylene-1-                                                                    1                                                    diphosphonic acid                                                                        amino pentane-1,1-diphos-                                                     phonic acid                                                    16  1-Hydroxy-3-amino                                                                        N,N-bis-phosphono meth-                                                                     3                                                    propane-1,1-di-                                                                          ylene-3-amino-1-hydroxy-                                           phosphonic acid                                                                          1,1-diphosphonic acid                                          17  1-amino-3-hydroxy                                                                        N-phosphono methylene-1-                                                                    1                                                    propane-1,1-                                                                             amino-3-hydroxy propane-                                           diphosphonic acid                                                                        1,1-diphosphonic acid                                          18  1-Amino-2-carboxy                                                                        N-phosphono methylene-1-                                                                    3                                                    ethane-1,1-diphos-                                                                       amino-2-carboxy ethane-                                            phonic acid                                                                              1,1-diphosphonic acid                                          19  1-Amino-3-phosphono                                                                      N-phosphono methylene-1-                                                                    1                                                    propane-1,1-diphos-                                                                      amino-3-phosphono prop-                                            phonic acid                                                                              ane-1,1-diphosphonic                                                          acid                                                           20  1,6-Diamino hexane-                                                                      N,N'-bis-phosphono meth-                                                                    1                                                    1,1,6,6-tetraphos-                                                                       ylene-1,6-diamino hexane-                                          phonic acid                                                                              1,1,6,6-tetraphosphonic                                                       acid                                                           __________________________________________________________________________

As stated hereinabove, the N-phosphono methylene amino alkane phosphonicacid compounds according to the present invention are usefulsequestering agents forming complex compounds with bi- and polyvalentmetals. They can advantageously be used, for instance, for preventingscale and deposit formation in aqueous media, as additives to cleansingsolutions, for instance, for cleaning and rinsing bottles, milk cans,and the like containers, in leather tanning for cleaning, stripping, andstain removal, in textile processing, for instance, as leveling agents,in dye baths, for instance, to prevent color distortion by metalimpurities, as additive to alkaline baths for treating fiber materialcomposed of or containing native cellulose such as cotton to inhibitdegradation of the cellulose chain, in peroxide bleaching baths asstabilizers, in the manufacture of paper to prevent pitch deposit, andfor many other purposes in which complexing, sequestering, and/orchelating agents are used. The following examples illustrate the mannerin which the phosphonic acid compounds according to the presentinvention can be employed without, however, limiting their usefulness tosaid examples.

EXAMPLE 23 Treatment of Water Used for Sterilization of Cans

Tin plate cans are placed into a 10 liter autoclave. Tap water of thefollowing composition is used for sterilization of the cans:

Total hardness: 25° (German degrees of hardness)

Carbonate hardness: 17° (German degrees of hardness)

Chlorides: 53° mg./liter

Sulfates: 85 mg./liter

Free carbon dioxide: 40 mg./liter

Bound carbon dioxide: 125 mg./liter

pH-value: 7.2

5 cc. of N-phosphono methylene-1-amino ethane-1,1-diphosphonic acid areadded to the tap water. Sterilization is effected by heating to 140° C.at about 4 atmospheres gauge. Addition of the phosphonic acid compoundinhibits scale and deposit formation on the sterilized cans as well ason the walls of the autoclave.

EXAMPLE 24

250 kg. of bleached sulfite cellulose pulp known for its property ofcontinuously causing difficulties due to resin deposition were beaten ina Hollander beater at a pulp consistency of 3% to about 78°Schopper-Riegler, i.e. so as to form a well beaten pulp suitable forproducing dense sheets of the parchment-like paper. The pH-value of theslurry was 6.0.

Before starting beating, 0.5 kg. of the sodium salt of N-phosphonomethylene-1-amino ethane-1,1-diphosphonic acid were added to the slurryin the Hollander beater. After beating, 0.8 kg. of the same sodium saltwere admixed thereto.

When proceeding in this manner, no resinous deposits were observed onthe walls of the Hollander beater, nor in the pipe lines, nor in thepaper machines.

The phosphonic acids according to the present invention can be used assequestering, complexing, and/or chelating agents for other purposes,for instance, as described in U.S. Pat. No. 3,860,391 in peroxidebleaching baths and U.S. Pat. Nos. 3,833,517 and 3,954,401 in baths forthe treatment of cellulose fiber materials, and for other uses for whichsuch agents have been used before. If desired, the alkali metal orammonium salts or solutions thereof can also be used in place of theacids. These salts are prepared by neutralizing the phosphonic acidswith the calculated amounts of alkali metal hydroxides or ammonia.

It may be mentioned that the alkali metal salts need not be prepared butthat the acids as such can be added to alkaline solutions.

Of course, many changes and variations in the starting materials used,the proportions of the reactants employed, the reaction duration andconditions, the manner of working up the reaction mixtures and products,their uses and the like may be made by those skilled in the art inaccordance with the aforesaid description of the invention and theclaims annexed hereto.

We claim:
 1. An N-phosphono methylene amino alkane phosphonic acidcompound of the formula ##STR7## in which n is a numeral from 0 to 4;R₁indicates alkyl with 1 to 11 carbon atoms in its hydrocarbon chain,hydroxyl, an alkylene phosphonic acid group of the formula--(CH₂)_(n).PO₃ H₂, the hydroxyethylene group of the formula --C₂ H₄ OH,an alkylene carboxylic acid group of the formula --(CH₂)_(n).COOH, anamino alkylene group of the formula ##STR8## or an 1-aminoalkyl-1,1-diphosphonic acid group of the formula ##STR9## or R₁ alsoindicates hydrogen in the case where n is 1-4 and in the case where n is0 and R₂ is the phosphonic acid group; R₂ indicates hydrogen or thephosphonic acid group; R₃ indicates hydrogen or the methylene phosphonicacid group; and R₄ indicates the methylene phosphonic acid group.
 2. Thecompound of claim 1, in whichn is 0, R₁ is hydrogen, R₂ is thephosphonic acid group, R₃ is hydrogen, and R₄ is the methylenephosphonic acid group,said compound being N-phosphono methylene aminomethane diphosphonic acid.
 3. The compound of claim 1, in whichn is 0,R₁ is methyl, R₂ is the phosphonic acid group, R₃ is hydrogen, and R₄ isthe methylene phosphonic acid group,said compound being N-phosphonomethylene-1-amino ethane-1,1-diphosphonic acid.
 4. The compound of claim1, in whichn is 1, R₁ is hydrogen, R₂ is hydrogen, and R₃ and R₄ are themethylene phosphonic acid group,said compound being N,N-bis-phosphonomethylene-1-amino ethane-2-phosphonic acid.
 5. The compound as definedin claim 1, whereinn is a numeral from 1 to 3 R₁ is hydrogen or the--PO₃ H₂ group R₂ is hydrogen or the --PO₃ H₂ group R₃ is hydrogen orthe --CH₂ PO₃ H₂ group and R₄ is the --CH₂ PO₃ H₂ group.
 6. The compoundas defined in claim 1, which is a N-phosphonic methylene-1-aminoalkane-1,1-diphosphonic acid, having the formula ##STR10## wherein R₁ 'indicates alkyl containing 1 to 11 carbon atoms.
 7. The compound asdefined in claim 1, which is aN-phosphonomethylene-1-amino-ω-carboxy-1,1-alkane-diphosphonic acid,having the formula ##STR11## wherein R₁ " indicates a --(CH₂)_(n) --COOHgroup wherein n is 0 to
 4. 8. The compound as defined in claim 1, whichis a N,N-bis-phosphonomethylene-diaminoalkane-tetra phosphonic acidhaving the formula ##STR12## wherein R₁ '" indicates a group of theformula ##STR13## and R₃ ' is hydrogen or a --CH₂ --PO₃ --H₂ group and nis 0-4.
 9. The compound as defined in claim 1, having the formula##STR14##
 10. The compound as defined in claim 1, having the formula##STR15##
 11. The compound as defined in claim 1, having the formula##STR16##
 12. The compound as defined in claim 1, having the formula##STR17##
 13. The compound as defined in claim 1, having the formula##STR18##
 14. The compound as defined in claim 1, having the formula##STR19##
 15. The compound as defined in claim 1, having the formula##STR20##
 16. The compound as defined in claim 1, having the formula##STR21##
 17. The compound as defined in claim 1, having the formula##STR22##
 18. The compound as defined in claim 1, having the formula##STR23##
 19. The compound as defined in claim 1, having the formula##STR24##
 20. The compound as defined in claim 1, having the formula##STR25##
 21. The compound as defined in claim 1, having the formula##STR26##
 22. The compound as defined in claim 1, having the formula##STR27##
 23. The compound as defined in claim 1, having the formula##STR28##
 24. The compound as defined in claim 1, having the formula##STR29##